Fireproof dirigible airship



July 9 1,929. T B SLATE f 1.720.382

FIREPROOF DIRIGIBLE AIRSHIP Filed April 28, 1926 2 Sheets-Sheet 2HTTORNEY Patented July 9, 1929.

UNITED STATES THOMAS B. SLATE, F GLENDALE, CALIFORNIA.

FIREPROOF DIRIGIBLE AIRSHIP.

i Original application filed July 23,' 1925, Serial No. 45,649. Dividedand this application filed April 28,

. 1926. Serial No. 105,279.

This application is a division of my application Serial 45,649, filedJuly 23, 1925, for an airship.

The object of my invention is to provide a novel means for controllinggas expansion and contraction due to changes in atmospheric pressure invarious altitudes and to changes of temperature of gases within theairship.

It is a further purpose of myinvention to provide a compensation bagthat is stationary with the center of buoyancy of the ship and whichwill not float toward the lower end of the ship and change or affect thebalance of the ship by allowing one end to get slightly lower than theother, thereby making the ship entirely rigid so far as air displacementis concerned, and causing it to float on an even keel of its own accordfor the reason that when one end is lower than the other it isdisplacing a denser atmosphere than the higher end of the ship, therebyeffecting greater lift and causing the ship to float back to an evenkeel.

It is a further object of my invention to provide a ship with liquefiedhydro-carbon fuel at a temperature and under a pressure that will makelarge quantities of fuel vapor available at any time that any emergencymay require its use, whereby to utilize the vapor expansion as a motivepower for starting the ships engines and for other purposes required bythe operators of the ship.

It is also an object of my invention to provide a ship having its fuelsupply carried partly in vapor form, the proportion of vapor to liquidbeing under the control of the operator to reducethe weight of the totalfuel supply and to control the balanceof gross lift of the ship over thegross weight of ship and cargo.

It is also my objectt'o provide novel means of utilizing the spaceoccupied by the compensation bag for fuel vapor to supply the power todrive the ship.

I attain the objects of my invention by the apparatus illustrated in theaccompanying drawings, in which Figure 1 is a diagrammatic View of myinvention, partly in side elevation and partly in section, with thedirection of air currents in dicated by arrows; A

Fig. 2 is an enlarged detail view in section of the compensation bagwith its centralcompartment inflated.

Fig3 is a similar view with the central compartment of the compensationbag deflated; y

Fig. 4 is a similar view with the compensation bag as a whole deflated;

Fig. 5 is a' longitudinal section through a larger ship than that shownin Fig. 1, showing a plurality of engines attached to the samepropeller, partly in elevation and showing a i compensation bag ofmodified shape;

Fig. 6 is a transverse section through an a-i-'rship of the type shownin Fig. 5.

Likenumerals designate like parts in the respective views.

Referring to the accompanying drawings, I provide an airship shell orcovering 1 of a suitable light metal approximately of the shape shown inFig. l and having a passenger and freight compartment 2 extendinglongitudinally of the shell ;l and a power plant compartment 3positioned at the forward end of the ship.

I provide a compensation bag 4 mounted at the center of buoyancy of theairship, immediately over the passenger and freight compartment. Thisdevice consists of a funnelshaped outside cover 5 extending from thebottom of the ship to a stationary ring 6 which is suitably braced bythe suspension wires 7 attached to the ribs or wall of the airship sothat the outside cover always keeps the same position in the ship asshown. Within the rigid shell 5 is a flexible gas bag, the flexibleportion or diaphragm 10 of which is contained within the shell 5 and theupper flexible portion or diaphragm 8 of which,.when inflated, extendsabove the ring 6 to form an inverted funnel-shaped bag. As shown inFigs. 2, 3 and 4, a space 40 is provided between the lower portion 10 ofthe flexible gas bag and the rigid shell 5.

I provide a gas compartment 39, which may be filled' with a power gassuch as natural gas, coal gas, or water gas, preferably natural gas orany other gas rich in heat units and vlighter than air. The purpose ofthis gas compartment is to utilize the space occupied by thecompensation bag to carry the fuel supply for the ship. The lower andouter funnel-shaped cover 5 of the compensation bag is provided with anoutlet 11 communieating with the atmosphere to allow air to breathe inand out in connection with chamber 40 between the diaphragm 10 of theliexible compensation bag and the rigid outer cover 5 to cause thediaphragm 10 to contract or expand as at 12. Outlet 11 is preferablyprovided with a valve`41.- Upper'diaphragm 8 of the compensation bagwill occupy practically its full position as indicated in Fig. 1 whenthe ship is at anchor near the ground. At the end of. a long trip thefuel gas between the lower diaphragm 10 of the compensation bag and theupper diaphragm 8 will have been mostly used up, and the lower diaphragm10 of the compensation bag will have risen to and occupy the positionindicated approximately by the dotted lines 9, as shown in Fig. l, andits relation to ring 6 will be as shown in Fig. 3. When the ship takes anew supply of fuel gas the diaphragm.

10` of the compensation bag will drop ap- (proxi'mately to the positionshown in Fig. 1 and in Fig. 2 with its lower portion at 12 and the shipwill be ready for another trip.

I provide suitable engines 57 in the power plant compartment 3. Iprovide an intake pipe 19 in connection with the interior of theflexible compensation bag as shown in Figs. .2,.3 and 4. Referring toFig. 1, I provide a valve-controlled relilling pipe 21 `in connectionwith the same compartment as pipe 19.

Referring to Fig. 8, I preferably provide a pulsating bag 43 incommunication with the fuel supply pipe 19 and with the pipe 45 lead`ing to the manifold 46 of engines 57. A valve 44 is provided in pipe 19,as shown. Engines 57 are operatively connected with fan shaft 56 by thechains 55. The fan shaft also carries the starting motor 49 which isoperated by the fuel pressure passing through pipe 47 from the liquefiedgas pressure tank 50. Tank 50 is surrounded by a suitable insulatingjacket 51. Jacket 51 is provided with vents 52 and 53 and a circulatingfan or blower 54 is provided in the path of one of these vents.

As shown in Fig. 8, I provide a passage- 'way 67 having suitable stepsor ladder to afford convenient access to the engine room.

Referring to Fig. 6, the car 2 isprovided witlrpassenger compartments 58and sleeping berths 59 andi-a central aisle 60.

The ship is supplied with fuel vapor such as natural gas, water gas, orany high grade manufactured gas, by filling the fuel gas compartment 391with the vapor through pipe 21; or by liquef'ying` the gas and'fillingtanks 50, illustrated .in Fig.'8. The liquid is reducedin temperatureOuntil its vaportension is at from 100` poundsJ .to 200 pounds persquare inch, or any other` convenient-pressure to be used through anexpansion engine or starting motor 49. This motor on a large ship may bemounted directly on the fan shaft-I to which is geared a number ofinternal combustion engines of ordinary aircraft design for any otherlight and powerful type of heat engine adapted to aircraft service. yThe excess gas from the starting engine is piped to the main gas linefrom the compensation bag to the engine so that the excess gas from thestart-ing engine may'flow directly to the manifold to supply theengines. Any surplus quantity of gas can iow back to the compensationbag as a storage supply. This may be regulated at the will of theoperator by allowing full pressure to flow through the engine deliveringpower directly to the fan shaft and filling up the compensation bag,thereby driving air out of the colnpensation bag through outlet 11 andpast valve 41 tothe atmosphere. The fuel vapor being lighter than airhas a tendency to cause the ship to rise. By throttling the supply ofgas to the engine down to a point below that necessary to supply themain engines with fuel will cause them to draw on the supply of gas inthe compensation bag, sucking inv air to take its place, thereby makingthe ship heavier and causing it to descend. If a great volume of gas isrequired momentarily it may, be had by opening'the throttlervalve 48wide and allowing the pressure in tank 50 to decrease. If a large volumeis required over a considerable period of time the rate of .evaporationin tank 50 may be increased by circulating hydrogen from the main bag orchamber of the ship through conduit 53 by means of fan 54 and outthrough conduit 52.

The circulation of the main volume of hydrogen through the insulation oftank 50 into temperatures below the freezing point will freeze outmoisture and other impurities collecting in the main volume of hydrogen.By equipping the-ship with a plurality of tanks 50, a tank may beallowed to run empty occasionally and thaw the collection of ice andother impurities from the kjacket. By this means a very pure supply ofhydrogen is maintained in shell l. The pipe 19 is equipped with a valve44 and the opening 11 is equippedV with a valve 41. In case of leakageor a puncture in the diaphragm 10 of the compensation bag, the valve 41may be closed and the compensation bag controlled by valve 44 tomaintain approximately atmospheric Apressure within the ship.y Or valve44 may be closed and valve 41 left open, allowing both compartmentsinthe compensation bag to fill I with air, compensation in weight beingthus obtained automatically without the use of the compensation bag as astorage chamber for fuel vapor. Either of these methods of operation mavbe used in emergency if leakage op other diiiculty in operation of thecompensation bag occurs.

At'landing stations a fresh supply of liquid gas is taken aboard theship as a cold liquid under little if any pressure and the tanks 50 arefilled and sealed so that as the temperature rises they will build up apressure to the point necessary for the operation of the/system.` Therate of evaporatlon may be increased Vby the circulation of the shipshydrogen through the insulation of the tanks to keep the necessaryamount of pressure. While the ship is standing at the station and theengines running only un der partial capacity to hold the ship in apractically stationary position against whatever amount of wind theremay be at the time, the liquid fuel is being vaporized and the largeamount of air space in the compensation bag is being displaced with fuelvapor which tends to make the ship lighter.

Vshen the airship is ready to leave a landing station a volume of fuelgas will be evap orated from its liquidstate and run into thecompensation bag, driving out a large volume of air from the bag andresulting in increased buoyancy of the airship and the ship starts onits'journey from the p'oint indicated as A in Fig. 5. The increasedbuoyancy resulting from the extra supply of fuel vapor in thecompensation bag will cause the ship to rise to a higher flying level asindicated diagrammatically by B in Fig. 9. When it is desired to havethe ship descend the evaporation of the liquid fuel gas is slowed downby the operator to a point where the engines are using the reserve fuelvapor from the compensation bag and a volume of air to admitted to thebag through vent or pipe 11. This decreases the buoyancy of the ship andresults in a natural descent to the next station or depot as indicatedat D in Fig. 9.

The conduits 11 and 19 to the compensation bag are equipped with valves41 and 44 which enable the operator to control the flow of fuel vaportothe engines and the intake of air to take its place is thecompensation bag as shown in Fig. 8. In.

emergency, control of the ship may be maintained as follows: Ifdiaphragm 8 should develop a leak, valve 44 may be closed and use of thefuel vapor compartment discontinued temporarily and the ship will getits compensation lautomatically by air flowing in and out through pipe11. If the compensation bag lower diaphragm 10 should develop a leak,valve 41 can be `closed and compensation effected completely with thefuel vapor through pipe 19. Or valve 44 may be closed and the entirespace occupied by air and fuel vapor in the compensation bag be filledwith air to effect compensation automatically through pipe 11.

Motors 34 and 31 used in the elevator sys-' tem are preferably turbineoperated from the fuel vapor of the liquid vapor system, therebylightening the weight of the machinery and improving' the control overthe buoyancy of the ship. The exhaust from the turbines is piped to thefuel vapor compartment of the compensation bag. The value of the turbineis that a l, predetermined amount of tension may be placed on guidewires 35 and the ship allowed to change position up and down and themotor caused to back up by increased ten sion on the wires orto take upwithdecreased tension on the wir-es without the attention of the`operator, maintaining the proper length of elevator cable at all times.i

The entire ship is metal and noninflammable and the main shell or casing1 may therefore be filled with hydrogen gas and be practically as safeas it would be with helium. Compensation for gas expansion in the shipis cared for by a fixed compensation bag in approximately the center ofAlift and in the lower half of the ship. This causes the ship to stand onan even keel of its own accord by reason of the fact that the ship isentirely rigid and if one end should occupy a position lower than theother it will be displacing heavier air and thereby have its liftingpower at that end increased. while the other end displacing lighter airwill have its lifting power decreased.

I provide suitable eross-bracing wires 14 aixed to the rings 66. Thistype of airship may be cross-braced in its cross-section b cross-bracingfrom one side to the other by staggered spokes as in a bicycle wheelwith what would correspond to the hub of the wheel being of considerablelength. and further braced longitudinally by crossing braces from onering to another throughout the length of the ship, except the smallportion occupied by the compensation bag.

What I cla-im is:

1. In an airship of the lighter than air type, the combination with anairship hull, of a compensation bag positioned in the lower portion ofthe ship at the center of buoyancy said compensation bag including arigid cupshaped member mounted in ay lixed position in the lower portionof the airship, a flexible bag mounted. in and attached to the upperedge of the aforesaid rigid cup-shaped member and providing a chamberbetween the aforesaid members, a conduit for supplying a` fuel gas tothe flexible bag, and a conduit 'for the flow of air to and fro-m thechamber between the rigid cup-shaped member and the lower portion of theflexible bag.

2. In an airship of the lighter than air type, the combination of arigid shell of noninfiammable material forming the main hull,

`a compensation bag positioned in the lower portion of the ship at theeenterof buoyancy, said compensation bag including a rigid cup-shapedmember mounted in a fixed position in the lower portion of the airship,a flexible bag mounted in and attached to the upper edge of theaforesaid rigid cup-shaped member and providing a chamber between theaforesaid members, a conduit for supplying a fuel gas to the flexiblebag, andv a conduit for the flow of air to an'd from the chamber betweenthe rigid cup-shaped member and the lower portion of the flexible bag.

8. In an airship of the lighter than air type, the combination with anairship hull, of

' portion of the ship at the center of buoyancy,

` and the lower portion of the flexible bag,

trolle'd means for supplying fuel gas 'from` the compensation bag tooperate the propelling means. n Y

4. In an airship of the lighter than air type, the combination of arigid shell of noninfiammable material forming the main hull, acompensation bagpositioned in the lower portionof the shipat the centerof buoyancy,

, said compensation bag including a rigid cupshaped member mounted in afixed position in the lower portion of the airship, a iexible bagmounted "in and attached to the upper edge of the aforesaid rigidcup-shaped member and providing a chamber between the two` members, aconduit for supplying fuel gas to the flexible'ba'g, a valve-controlledconduit for the flow of air to and from the chamber y between the rigidcup-shaped member means for propelling the airship,`and valvecontrolledmeans for supplying fuel gas from 4ling means.

the compensation bag to operate thepropel- 5. An airship of the lighterthan air type havingca compensation bag permanently fastened at thecenter of buoyancy of the airslip, the lower half of the bag being arigid s ell.

6. In an airship of the lighter than air type, the combination of acompensation bag having its lower half formed of a rigid shell affixedat the center of buoyancy of the airship and having the upper half ofthe compensation bag of flexible material adapted to float up or down tocompensate for variation in pressure iii/side the ship depending onvariation in atmospheric pressure outside the ship, and having a passageat its lower extremity communicating with the outside atmosphere.

7 In combination with the apparatus disclosed in claim 6, a fiexiblediaphragm placed inside the compensation bag between the upper andVlower half thereof to providean airtight chamber for the reception offuel gas.

8. In combination with an airship of the light-er than air type, acompensation bag having its lower half formed of a metallic lire--proofshell permanently fastened at the center of buoyancy of the ship,and a plurality of flexible diaphragms affixed in spaced relation' tothe metal shell near the edge thereof whereby to provide a plurality ofchambers in the compensation bag.

THOMAS B. sLATE.

